18 EXP
Darkside is the first boss you fight.lock onto one of his hands (R1) and start chopping away at it. This Darkside has two attacks. One that where he puts his hand into the arena and darkness pours out of it. This is the best time to strike, so charge through the blackness and combo until he lifts his hand again. His other attack is a homing energy ball attack. Jump when the ball gets too close for comfort. This boss is more an event battle than a true boss, but inexperienced players may have trouble.
30 EXP
If you win or lose this fight, it doesn't matter. If you do want that 30 EXP then here's the guide:
First make sure you have a potion or two equipped. Now, jump over leon after he does an attack, hit him from the back ONLY! When you see him aim his sword jump or dodge roll to get out of the way. That's all thee is to it.